#!/usr/bin/env python3
# Copyright (c) 2014-2022 The Bitcoin Core developers
# Distributed under the MIT software license, see the accompanying
# file COPYING or http://www.opensource.org/licenses/mit-license.php.
"""Test spending coinbase transactions.

The coinbase transaction in block N can appear in block
N+100... so is valid in the mempool when the best block
height is N+99.
This test makes sure coinbase spends that will be mature
in the next block are accepted into the memory pool,
but less mature coinbase spends are NOT.
"""

from decimal import Decimal
from test_framework.blocktools import COINBASE_MATURITY
from test_framework.test_framework import BitcoinTestFramework
from test_framework.util import assert_equal, assert_raises_rpc_error
from test_framework.wallet import MiniWallet
from test_framework.qtumconfig import *


class MempoolSpendCoinbaseTest(BitcoinTestFramework):
    def set_test_params(self):
        self.num_nodes = 1

    def run_test(self):
        wallet = MiniWallet(self.nodes[0])

        # Invalidate two blocks, so that miniwallet has access to a coin that will mature in the next block
        chain_height = 2098
        self.nodes[0].invalidateblock(self.nodes[0].getblockhash(chain_height + 1))
        assert_equal(chain_height, self.nodes[0].getblockcount())

        # Coinbase at height chain_height-100+1 ok in mempool, should
        # get mined. Coinbase at height chain_height-100+2 is
        # too immature to spend.
        coinbase_txid = lambda h: self.nodes[0].getblock(self.nodes[0].getblockhash(h))['tx'][0]
        utxo_mature = wallet.get_utxo(txid=coinbase_txid(chain_height - COINBASE_MATURITY + 1))
        utxo_immature = wallet.get_utxo(txid=coinbase_txid(chain_height - COINBASE_MATURITY + 2))

        spend_mature_id = wallet.send_self_transfer(from_node=self.nodes[0], fee_rate=Decimal("0.03"), utxo_to_spend=utxo_mature)["txid"]

        # other coinbase should be too immature to spend
        immature_tx = wallet.create_self_transfer(fee_rate=Decimal("0.03"), utxo_to_spend=utxo_immature)
        assert_raises_rpc_error(-26,
                                "bad-txns-premature-spend-of-coinbase",
                                lambda: self.nodes[0].sendrawtransaction(immature_tx['hex']))

        # mempool should have just the mature one
        assert_equal(self.nodes[0].getrawmempool(), [spend_mature_id])

        # mine a block, mature one should get confirmed
        self.generate(self.nodes[0], 1)
        assert_equal(set(self.nodes[0].getrawmempool()), set())

        # ... and now previously immature can be spent:
        spend_new_id = self.nodes[0].sendrawtransaction(immature_tx['hex'])
        assert_equal(self.nodes[0].getrawmempool(), [spend_new_id])


if __name__ == '__main__':
    MempoolSpendCoinbaseTest(__file__).main()
